import 'package:english_words/english_words.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    if (Theme.of(context).platform == TargetPlatform.android) {
      // android 平台
      SystemUiOverlayStyle _style =
      SystemUiOverlayStyle(statusBarColor: Colors.transparent);
      SystemChrome.setSystemUIOverlayStyle(_style);
    }
    SystemUiOverlayStyle systemUiOverlayStyle = SystemUiOverlayStyle(statusBarColor:Colors.transparent);
    SystemChrome.setSystemUIOverlayStyle(systemUiOverlayStyle);
    return new MaterialApp(
      home: new RandomWords(),
      theme: new ThemeData(
        primaryColor: Colors.white,
      ),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key? key, required this.title}) : super(key: key);

  // This widget is the home page of your application. It is stateful, meaning
  // that it has a State object (defined below) that contains fields that affect
  // how it looks.

  // This class is the configuration for the state. It holds the values (in this
  // case the title) provided by the parent (in this case the App widget) and
  // used by the build method of the State. Fields in a Widget subclass are
  // always marked "final".

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int _counter = 0;

  void _incrementCounter() {
    setState(() {
      // This call to setState tells the Flutter framework that something has
      // changed in this State, which causes it to rerun the build method below
      // so that the display can reflect the updated values. If we changed
      // _counter without calling setState(), then the build method would not be
      // called again, and so nothing would appear to happen.
      _counter++;
    });
  }

  @override
  Widget build(BuildContext context) {
    // This method is rerun every time setState is called, for instance as done
    // by the _incrementCounter method above.
    //
    // The Flutter framework has been optimized to make rerunning build methods
    // fast, so that you can just rebuild anything that needs updating rather
    // than having to individually change instances of widgets.
    return Scaffold(
      appBar: AppBar(
        // Here we take the value from the MyHomePage object that was created by
        // the App.build method, and use it to set our appbar title.
        title: Text(widget.title),
        elevation: 0,
      ),
      body: Center(
        // Center is a layout widget. It takes a single child and positions it
        // in the middle of the parent.
        child: Column(
          // Column is also a layout widget. It takes a list of children and
          // arranges them vertically. By default, it sizes itself to fit its
          // children horizontally, and tries to be as tall as its parent.
          //
          // Invoke "debug painting" (press "p" in the console, choose the
          // "Toggle Debug Paint" action from the Flutter Inspector in Android
          // Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
          // to see the wireframe for each widget.
          //
          // Column has various properties to control how it sizes itself and
          // how it positions its children. Here we use mainAxisAlignment to
          // center the children vertically; the main axis here is the vertical
          // axis because Columns are vertical (the cross axis would be
          // horizontal).
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              'You have pushed the button this many times:',
            ),
            Text(
              '$_counter',
              style: Theme.of(context).textTheme.headline4,
            ),
          ],
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _incrementCounter,
        tooltip: 'Increment',
        child: Icon(Icons.add),
      ), // This trailing comma makes auto-formatting nicer for build methods.
    );
  }
}

class RandomWords extends StatefulWidget {
  @override
  State<StatefulWidget> createState() {
    // TODO: implement createState
    // throw UnimplementedError();
    return new RandomWordsState();
  }

}

class RandomWordsState extends State<RandomWords> {
  final _suggestion = <WordPair>[];
  final _biggerFont = const TextStyle(color: Colors.red);
  final _saved = new Set<WordPair>();
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    // final wordPair = new WordPair.random();
    // return new Text(wordPair.asPascalCase + '你不好');
    return new Scaffold(
      appBar: new AppBar(
        centerTitle: true,
        title: new Text('flutter学习'),
        actions: <Widget>[
          new IconButton(
            icon: new Icon(Icons.list),
            onPressed: _pushSaved,
          ),
          new IconButton(
            icon: new Icon(Icons.accessible),
            onPressed: _pushSaved,
          ),
        ],
      ),
      body: _builSuggestions(),
    );
  }

  void _pushSaved () {
    Navigator.of(context).push(
      new MaterialPageRoute(
          builder: (context) {
            final tiles = _saved.map((pair) {
              return new ListTile(
                title: new ListTile(
                  title: new Text(
                    pair.asPascalCase,
                    style: _biggerFont,
                  ),
                ),
              );
            },
           );
           final divided = ListTile
             .divideTiles(
               tiles: tiles,
               context: context,
             )
             .toList();

           return new Scaffold(
             appBar: new AppBar(
               title: new Text('我的收藏'),
               centerTitle: true,
             ),
             body: new ListView(children: divided),
           );
        },
      ),
    );
  }

  Widget _builSuggestions() {
    return new ListView.builder(
      padding: const EdgeInsets.all(16.0),
      itemBuilder: (context, i) {
        if(i.isOdd) return new Divider();

        final index = i~/2;
        if(index >= _suggestion.length) {
          _suggestion.addAll(generateWordPairs().take(10));
        }
        return _buildRow(_suggestion[index]);
      },
    );
  }

  Widget _buildRow(WordPair pair) {
    final alreadySaved = _saved.contains(pair);
    return new ListTile(
      title: new Text(
        pair.asPascalCase,
        style: _biggerFont,
      ),
      trailing: new Icon(
        alreadySaved ? Icons.favorite : Icons.favorite_border,
        color: alreadySaved ? Colors.red : Colors.blue,
      ),
      onTap: () {
        setState(() {
          if(alreadySaved) {
            _saved.remove(pair);
          } else {
            _saved.add(pair);
          }
        });
      },
    );
  }
}